Long time Chicago resident and very familiar with the area and the community. Your drive parameters may, just like others have said, be a little too rigid because between weather and Chicago traffic what comes up as 40 minutes on Google Maps could turn into two hours depending on conditions. BUT, there are definitely barns that are worth it.
On Course Riding Academy - Valerie Buesching
Our Day Farm - Maggie Jayne
Red Coat Farm - Lisa Goldman
Millennium Farm - Katie Leverick
Third Coast Equestrian - Alex Veleris
Old Barrington Farm - Amelia McArdle
Deerwood Farm - Erin Hirsch
Fireside Farm (Dressage) - Patti Becker
Flying Dutchman Farm (Dressage) - Rosie Simoes and Julie Julian
Hidden Knoll Farm - Jill Knowles
Always Faithful Equestrian Center - John French
Galway Farm - Laurie Canaday
Some others:
Palladia Farm, Glen Grove Equestrian Center, Involo Farms, Victorious Farms, Campton Hills Equestrian, Seven Oaks Farm, Townline Stables, Messenger Hill Farm, Lane Williamson Stables, Fields & Fences, High Finance Farm
I will say you will most likely have much more luck with lessons/leases with the hunter/jumper barns. The dressage community has very few, if any lesson programs currently in the area. Unless you’re willing to go very far West or North.
Check the member directories for the Northern Illinois Hunter Jumper Association, the Illinois Hunter Jumper Association, and the Illinois Dressage and Combined Training Association.
Good luck!